This invention concerns snowshoes of the type having a peripheral tubular frame suspending a flexible deck. Specifically the invention concerns such a snowshoe frame having added strength in certain regions to resist forces tending to deform the shape of the frame.
Snowshoes of the general type with which this invention is concerned are shown in Atlas Snowshoe Company U.S. Pat. Nos. 5,440,827, 5,687,491, 5,699,630, 5,901,471, 6,374,518, 6,401,310, 6,505,423, 6,526,629 and 6,725,576. These patents show a peripheral frame of tubular metal, usually aluminum, with cylindrical cross section, bent and formed into the desired configuration and usually welded together at the tail end, but sometimes connected instead by a separate tail member that engages with the tube tail ends of the tubular frame (as in U.S. Pat. No. 6,725,576). In this type of snowshoe, a flexible deck membrane is supported in considerable tension from the frame, by a series of connection points at which the deck membrane loops over the frame or another piece of material extends over the frame and is secured, as by rivets, to the deck membrane.
In addition, in typical snowshoes of the above patents, the binding and the front cleat are secured to the snowshoe frame by tension bands that orient the binding and cleat in an obliquely angled toe-down position relative to the snowshoe frame. These tension bands exhibit considerable inward pulling force on the frame, with the frame supplying a strong spring force pulling outwardly on the tension bands (which are substantially inelastic). As this strong spring force is needed to maintain proper suspension of the front cleat and boot binding, the frame needs to be provided with sufficient strength, particularly in the nose loop of the frame, which is just forward of the point of tension band suspension on the frame. Otherwise the nose loop of the frame will too readily give and allow the frame to pull inwardly at the binding support points so that the binding suspension will not function properly.
It is an object of the invention to provide for increased strength in certain areas of the snowshoe frame, particularly the nose loop, without requiring heavier gauge or larger-diameter tubing.